Coupling between electrohydrodynamic flow and electrostrictive cavitation in dielectric liquids under pulsed excitation

Cavitation due to electrostriction is an underlying mechanism of the electrical breakdown of dielectric liquids under nanosecond pulsed electric field. Studies have been conducted on electrohydrodynamic flows in this system resulting in negative pressure and, separately, cavitation initiation and development under negative pressure. Our work attempts to explore the coupled dynamics between the two processes. Specifically, we consider two feedback from the cavitation dynamics to the electrohydrodynamic equations. First, there is a modification of dielectric permittivity in the cavitation zone. Second, the generation and expansion of cavities can relieve negative pressure. On the other hand, the electrohydrodynamic equations links the flow characteristics with the pulsed electric field excitation. For a simple spherically-symmetric system, we show the effects of the couplings, one of which is the accelerated saturation of cavitation. Our preliminary results also suggest the possibility of controlling cavitation by adjusting the duration and ramp rate of the pulsed electric field.